syncevo/installcheck-local.sh in syncevolution before 1.3.99.7 uses mktemp to create a safe temporary file but appends a suffix to the original filename and writes to this new filename, which allows local users to overwrite arbitrary files via a symlink attack on the new filename.

References

• https://nvd.nist.gov/vuln/detail/CVE-2014-1639
• https://exchange.xforce.ibmcloud.com/vulnerabilities/90662
• http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=736357
• http://www.openwall.com/lists/oss-security/2014/01/22/3
• http://www.openwall.com/lists/oss-security/2014/01/22/4
• http://www.osvdb.org/102380
• http://www.securityfocus.com/bid/65098